Nucleus CMS is an open-source blog management software package written in PHP,[1] with a MySQL backend.

With a little tweaking (mainly to skins), it might be considered[2] a lightweight content management system.

[3] Nucleus makes use of a callback function which has led to a plugin system in multiple languages.

[4][5] The general drive within the development community is that functionality should exist as plugins as totally as possible.

This philosophy has led to a relatively light and uncluttered base install.